Embodiments of the inventive concept relate generally to a dynamic voltage and frequency scaling (DVFS) technique. More particularly, certain embodiments of the inventive concept relate to a method of performing a DVFS operation, an application processor performing the DVFS operation, and a mobile device comprising the application processor.
Mobile devices commonly include an application processor for controlling operations of one or more functional modules. Such functional modules may include, for instance, a communication module, a multimedia module, and so on. Because mobile devices generally use a battery for power, there is a general demand for the application processor and the functional modules to consume a low amount of power. Nevertheless, the application processor often consumes a relatively high amount of power compared to other components in the mobile device. Thus, many mobile devices employ a DVFS technique that predicts an operating state of a central processing unit (CPU) in the application processor and dynamically changes an operating frequency and an operating voltage of the application processor based on the predicted operating state.
Where a DVFS operation is performed for the application processor in the mobile device, the application processor provides operating frequency information indicating a change (i.e., an increase or a decrease) of the operating frequency to a power management integrated circuit (PMIC). The operating frequency information is generated based on a predicted operating state of the CPU, and the PMIC changes the operating voltage of the application processor based on the operating frequency information.
In conventional DVFS techniques, interaction between the application processor and the PMIC may have limited speed due to software such as an operating system (OS), which controls interactions between the application processor and the PMIC. As a result, the conventional DVFS techniques may fail to change, in real-time, the operating frequency and the operation voltage of the application processor based on the predicted operating state.